Pycnodysostosis - Contents | Cases | Comments | Bibliography

Pycnodysostosis

Comments

Perhaps we mean pyknodysostosis ( aka "pygmy"-dysostosis :> )
http://www.stepstn.com/cgi-win/nord.exe?proc=GetDocument&rectype=0&recnum=1017

To check if you are a sufferer.... http://www.ibionet.com/rarediseases/Pyknodysostosis.html
David Choon
University Malaya

http://www.csmc.edu/genetics/skeldys/nomen.4.html To find out the single inborn error of metabolism that results in pyknodysostosis

David Choon
University Malaya

dear colleague,
you can try a well padded pop cast ,rather then go for surgery. if you want some surgery, Syme's amputation is the best one.

A quick look at OMIM (Online Mendelian inheritance in Man) gives an explanation of PYKNODYSOSTOSIS
http://www.ncbi.nlm.nih.gov/htbin-post/Omim/dispmim?265800. Includes articles of relevance. May be of some help.
OMIM is an excellent resource and worth a look for all those weird and wonderful genetic diseases.
Christian Veillette
Orthopaedic Resident
University of Toronto

> Please advise me on the management of this 56 year old male, suffering
from Picnodysostosis. (M.Roos)

Now that we have all found the place in the book (thanks to Christian Veillette and David Choon) perhaps we should return to the original question from Marthinus Roos.
Is there anything about the genetics of this condition that indicates particular susceptibility to bone infections? or difficulty in treating one? If this patient didn't have Pyknodysostosis what would we do? Do any of the physiotherapists on the list have any suggestions about the problem of mobilizing him while he is recovering from the surgery on his thumb? Would a gutter crutch be helpful? If you think that his mode of ambulation was putting so much stress on the hand and thumb that it promoted the current problem a gutter crutch might be a good long term idea.
Do you have positive cultures?
Myles Clough mylesclough@shaw.ca 
Orthopaedic Surgeon, Kamloops, BC, Canada

Pyknodysostosis is probably quite similar to osteopetrosis. If so , I would treat as if he were just another patient and ignore the metabolic defect. As Miles suggests,there is possibly another cause for the infection such as
pressure from his difficulty with ambulation ( not clear why he cannot walk - is it because of his sinus only?) or other predisposition such as occupation or other diseases such as diabetes. Or is it because he has infection with an exotic organism such as in melioidosis ( Pseudomonas/Burkholderia pseudomallei ) . The possibililties are many.
David Choon
University Malaya

a little more about picnodysostosis.
As there should be no medullary canal formation, the suseptibilty to infection becomes high ( poor medullary blood supply).
In this way it is more like Osteopetrosis, where osteomyelitis of mandible is very common following any tooth infection.
Dr.Vinod Naneria
Orthopaedic Surgeon
Choithram Hospital & Research Centre,Indore
India
vnaneria@vsnl.com 

Henri Toulouse-Lautrec, the French Artist, had Pyknodysostosis.
Chris Vertullo
Arthroplasty Fellow
Toronto

Some of the articles I found indicated there was considerable controversy over whether this was the case or not. (? Toulouse-Lautrec having the condition)
Myles Clough mylesclough@shaw.ca 
Orthopaedic Surgeon, Kamloops, BC, Canada

Editor's comment

Looking through the abstracts of the literature available in Medline, it was noticeable how many papers there are about dental infections in pycnodysostosis. The genetic defect is nonsense or missense of the Cathepsin K gene. Is Cathepsin K involved in immune or inflammatory reactions? It is certainly involved in osteoclast activity.
Vinod Naneria suggested that the high incidence of bone infection in this condition (and osteopetrosis) was due to loss of the medullary canal and loss of the medullary blood supply. Is this generally accepted?

Myles Clough